1. Field of the Invention
The present invention relates to an apparatus and method for determining a position of a sensor node in a location service based system. More particularly, the present invention relates to an apparatus and method for determining a position of a device connected through a gateway, i.e., a terminal (e.g., a sensor node) whose routing is impossible to an Internet Protocol (IP) address, using the Open Mobile Alliance (OMA) standard in a location service based system.
2. Description of the Related Art
Generally, a mobile communication system has a related function unit for determining a position of a terminal in a mobile communication network and, by periods or according to a request, provides a location service forwarding a position of a terminal to a constant entity.
A network structure associated with a location service may differ depending on an internal network structure of 3rd Generation Partnership Project (3GPP) or 3GPP2 and the like. As a method for determining a present position of a terminal, there are a method of forwarding an identifier of a cell to which a terminal belongs, a method of, after measuring time during which signals reach each adjacent BS from a terminal, determining a position of the terminal using triangulation, a method using a Global Positioning System (GPS), and the like.
In order to provide a location service to a user, many signals are forwarded between a terminal and a server. Accordingly, standardized positioning technologies for providing a location service are under development. One of these technologies is Secure User Plane Location (SUPL) defined in OMA.
Commonly, an SUPL network includes an SUPL agent, an SUPL Location Platform (SLP), an SUPL Enabled Terminal (SET), and the like. The SUPL agent is a logical service access point that uses position information of an actually determined SET. The SLP is an SUPL service access point of a network part which accesses network resources to obtain the position information of the SET. The SET is an entity capable of communicating by an Internet Protocol (IP) address with the SUPL network that uses an SUPL interface. The SET interworks with a network through a user plane bearer and supports procedures defined in SUPL.
The SLP, a network constituent element, includes an SUPL Positioning Center (SPC) that is an entity determining an actual location, and an SUPL Location Center (SLC) that is an entity performing roaming and resource management and the like. Also, a location service based system can be realized in a proxy mode and a non-proxy mode. The proxy mode is a mode in which the SET communicates with the SLC itself to determine a position. The non-proxy mode is a mode in which the SET communicates with the SLC via the SPC to determine a position.
On the other hand, the SUPL, a technology defining a technique of position determination in an IP network, is now considering only a terminal (i.e., SET) having an IP address as a position determination target. However, due to the advent of various location services, position determination enhancement is required and together, a technology for determining a position of a terminal (hereinafter, referred to as a Sensor Node (SN)) whose routing to an IP address is impossible is increasingly needed. Also, communication between an SUPL network and an SN should go through a gateway, so there is a need to consider this in an existing position determination protocol.